Shifts in blood volume alter the perception of posture: further evidence for somatic graviception
Shifts in blood volume alter the perception of posture: further evidence for somatic graviception
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DOI：
10.1016/s0167-8760(01)00184-2
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发表时间：
2002-04-01
影响因子：
3
通讯作者：
Baisch, F
中科院分区：
文献类型：
--
作者：
Vaitl, D;Mittelstaedt, H;Baisch, F
本文探讨了自己的身体位置的感知和流体的分布之间的关系沿着受试者的脊柱（z-）轴。报告了两个实验。第一个是Vaitl等人研究的复制[J. Psychophysiol. 27（1997）99]，其已经显示由施加在下半身上的下半身正压（LBPP：+30 mmHg）或下半身负压（LBNP：-30 mmHg）引起的进入或离开胸腔的血容量的变化分别导致受试者感觉头向上或头向下倾斜。第二个实验的目的是区分耳石和液体分布的变化对身体位置的感知的影响，通过雪橇离心机结合LBPP和LBNP。在两个实验中，通过阻抗体积描记法测量胸腔内血液分布的变化。40名健康志愿者（17名女性）参加了实验1。他们被放置在一个可倾斜的板上的一侧（右耳向下的头部位置），受试者和实验者可以通过遥控器围绕受试者的z轴倾斜。受试者被要求旋转板，直到他们觉得他们处于水平姿势。结果清楚地表明，姿势的感知受到血液分布变化的影响。在LBNP期间，受试者感知到头部向上倾斜，而LBPP使他们感觉到头部向下倾斜。因此，重复了1997年研究中获得的结果。14名男性自愿参加实验2。以与实验1中相同的方式将它们定位在离心机上的滑板上。雪橇可以通过受试者和实验者的远程控制来移动。当离心机旋转时（ω = 2 π乘以每秒0.6转），要求受试者移动滑板，直到他们感觉自己处于水平位置。与实验1一样，LBPP和LBNP诱导了血容量的变化。双耳轴（耳石的位置）和离心轴之间的距离作为指示主观水平位置的依赖性测量。由于施加在身体上的额外离心力，血容量的变化比仅产生重力的实验I中更明显。姿势感知的变化受到耳石和流体分布的影响，两者以补偿的方式相互作用。这些结果再次证实了来自心血管系统的传入输入在身体姿势的感知中起主要作用的证据。这种重力感受现象需要进一步阐明传入输入的起源和所涉及的重力感受器（机械感受器）的部位和类型。(C)出版社：Elsevier Science B. V.
This article examines the relation between the perception of one's own body position and the distribution of fluid along the subject's spinal (z-) axis. Two experiments are reported. The first one is a replication of the Vaitl et al. study [J. Psychophysiol. 27 (1997) 99] which has shown that changes in shifts of blood volume into or out of the thoracic cavity induced by lower body positive pressure (LBPP: + 30 mmHg) or lower body negative pressure (LBNP: -30 mmHg) exerted on the lower body led subjects to feel tilted head-up or head-down, respectively. The second experiment was designed to differentiate between the influence of the otoliths and of the changes in fluid distribution on the perception of body position by means of a sled centrifuge in combination with LBPP and LBNP. In both experiments, changes in blood distribution within the thoracic cavity were measured by impedance plethysmography. Forty healthy volunteers (17 females) participated in experiment 1. They were positioned on the side (right-ear-down head position) on a tiltable board which the subject and the experimenter could tilt via remote control around the subjects' z-axis. Subjects were asked to rotate the board until they felt they were in a horizontal posture. The results clearly show that the perception of posture is influenced by the shift in blood distribution. During LBNP subjects perceived being tilted head-up, whereas LBPP led them feel tilted head-down. Thus, the results obtained in the 1997 study were replicated. Fourteen males volunteered in experiment 2. They were positioned on the sled on a centrifuge in the same manner as in experiment 1. The sled could be moved via remote control by both the subject and the experimenter. While the centrifuge rotatcd (omega = 2 pi times 0.6 rotations per second) the subjects were asked to move the sled until they felt they were in a horizontal position. As in experiment 1, shifts in blood volume were induced by LBPP and LBNP. The distance between the binaural axis (position of the otoliths) and the centrifuge axis served as dependent measure indicating the subjective horizontal position. Due to the additional centrifugal forces exerted on the body the shifts in blood volume were more pronounced than in experiment I where only gravitational forces were produced. The changes in the perception of posture were influenced by both the otoliths and the fluid distribution in such a way that both interact in a compensatory manner. These results again corroborate the evidence that afferent inputs from the cardiovascular system play a major role in the perception of the body posture. This phenomenon of graviception needs to be further elucidated with respect to the origins of the afferent inputs and the site and type of graviceptors (mechanoreceptors) involved. (C) 2001 Published by Elsevier Science B.V.